Ramp arrangement and method for measuring the position of an actuator in a rotating media data storage device

Abstract

Ramp arrangements and methods in accordance with the present invention can provide the position or velocity of an actuator assembly in a rotating media data storage device while loading or unloading a head connected with the actuator assembly from a disk. One such arrangement includes a conductive ramp electrically coupled to a conductive suspension lift tab such that a closed circuit is formed when the head is unloaded from the disk. As the suspension lift tab slides along the ramp, the resistance of the circuit changes. By measuring multiple positions at multiple times, a head velocity can be determined.

1. A method for measuring the velocity of a read/write head in a data storage device having a rotatable medium and a ramp, the read/write head being capable of communicating with the rotatable medium when in communicative proximity with the rotatable medium, and the ramp being capable of removing the read/write head from communicative proximity with the rotatable medium, the method comprising:
 using an actuator with which the read/write head is connected, at least a portion of said actuator being electrically connected with said ramp such that a circuit is formed when said portion contacts the ramp;  
 measuring a first resistance of said circuit for a first position of said portion on said ramp at a first time;  
 measuring a second resistance of said circuit for a second position of said portion on said ramp at a second time;  
 calculating a difference in resistance between the first resistance and the second resistance;  
 determining a change in position based on the difference in resistance;  
 calculating a difference in time between the first time and the second time; and  
 calculating the velocity of said read/write head by dividing the change in position by the difference in time.  
 
   
   
     2. The method of  claim 1 , wherein said portion of said actuator is a suspension lift tab. 
   
   
     3. The method of  claim 1 , wherein said portion of said actuator is a suspension. 
   
   
     4. A method for monitoring the motion of a read/write head in a data storage device having a rotatable medium and a ramp, the read/write head capable of communicating with the rotatable medium when in communicative proximity with the rotatable medium, and the ramp capable of removing the read/write head from communicative proximity with the rotatable medium, the method comprising:
 using an actuator with which the read/write head is connected, at least a portion of said actuator being electrically connected with the ramp such that a circuit is formed when said portion contacts the ramp;  
 measuring a resistance of said circuit; and  
 calculating a position of said read/write head based on the resistance.  
 
   
   
     5. The method of  claim 4 , further comprising:
 measuring a first resistance at a first time;  
 measuring a second resistance at a second time; and  
 calculating a change in position based on a difference between the first resistance and the second resistance.  
 
   
   
     6. The method of  claim 5 , wherein the method further comprises:
 calculating a change in time from the first time to the second time; and  
 calculating a velocity by dividing the change in position by the change in time.  
 
   
   
     7. The method of  claim 4 , wherein said portion is a suspension lift tab. 
   
   
     8. The method of  claim 4 , wherein said portion is a suspension.